Yes, I'm focused on 'water duration adjustment.'
I think I figured it out:
This is an adjustment that does not affect the soil moisture 'banking system.' I.e., the soil moisture numbers assume 'water duration adjustment' is at zero.
If one sets 'water duration adjustment' for a zone to other than zero, more water, or less water, will actually be put down that what is reflected in the soil moisture numbers.
As I increasingly understand the principles of ET controllers, if I'm correct, this makes sense. (And is one of the few ways to put down more or less water than what's called for in the soil moisture numbers.)
I think ideally, customers would be so perfect in their soil, plantings and irrigation characteristics that they wouldn't use 'water duration adjustment.' As I survey my property it's obvious I'm not smart enough (yet) to accurately identify exact settings I need. I'm lacking irrigation in some areas - it's pretty obvious. Thus, I'll use increased 'water duration adjustment' as an immediate adjustment 'knob' while continuing to search for the correct knobs. With success I'll put the adjustment knob back to zero.
Thank you for the Labor Holiday response!